measurement-dynamic-scapular-kinematics-using-an-acromion-marker

Measurement of Dynamic Scapular Kinematics Using an Acromion Marker Cluster to Minimize Skin Movement Artifact

The measurement of dynamic scapular kinematics is complex due to the sliding nature of the scapula beneath the skin surface. The aim of the study was to ...

University of Southampton

To develop a new assessment procedure, the Southampton Hand Assessment Procedure (SHAP), that allows contextual results of hand function to be obtained readily in a clinical environment.

Establishing a standardized clinical assessment tool of pathologic and prosthetic hand function: normative data, reliability, and validity.

To describe the wrist kinematics during movement through free range of motion and activities of daily living using a cyclical task.

Marker placement to describe the wrist movements during activities of daily living in cyclical tasks.

The surgeon Ambroise Paré designed an anthropomorphic hand for wounded soldiers in the 16th century. Since that time, there have been advances in technology through the use of computer-aided design, modern materials, electronic controllers and sensors to realise artificial hands which have good functionality and reliability. Data from touch, object slip, finger position and temperature sensors, mounted in the fingers and on the palm, can be used in feedback loops to automatically hold objects. A study of the natural neuromuscular systems reveals a complexity which can only in part be realised today with technology. Highlights of the parallels and differences between natural and artificial hands are discussed with reference to the Southampton Hand. The anatomical structure of parts of the natural systems can be made artificially such as the antagonist muscles using tendons. Theses solutions look promising as they are based on the natural form but in practice lack the desired physical specification. However, concepts of the lower spinal loops can be mimicked in principle. Some future devices will require greater skills from the surgeon to create the interface between the natural system and an artificial device. Such developments may offer a more natural control with ease of use for the limb deficient person.

Sensory motor systems of artificial and natural hands.

A model of the upper extremity is developed in which the forearm is constrained to lie in a horizontal plane and electrical stimulation is applied to the triceps muscle. Identification procedures are described to estimate the unknown parameters using tests that can be performed in a short period of time. Examples of identified parameters obtained experimentally are presented for both stroke patients and unimpaired subjects. A discussion concerning the identification's repeatability, together with results confirming the accuracy of the overall representation, is given. The model has been used during clinical trials in which electrical stimulation is applied to the triceps muscle of a number of stroke patients for the purpose of improving both their performance at reaching tasks and their level of voluntary control over their impaired arm. Its purpose in this context is threefold: Firstly, changes occurring in the levels of stiffness and spasticity in each subject's arm can be monitored by comparing frictional components of models identified at different times during treatment. Secondly, the model is used to calculate the moments applied during tracking tasks that are due to a patient's voluntary effort, and it therefore constitutes a useful tool with which to analyze their performance. Thirdly, the model is used to derive the advanced controllers that govern the level of stimulation applied to subjects over the course of the treatment. Details are provided to show how the model is applied in each case, and sample results are shown.

A model of the upper extremity using FES for stroke rehabilitation.

User perceptions are critical, yet often ignored factors in the design and development of rehabilitation technologies. In this article, measures for collection of patient perceptions are developed and applied to a novel upper limb workstation that combines robotic therapy and electrical stimulation (ES).

Stroke participants' perceptions of robotic and electrical stimulation therapy: a new approach.

A survey of the literature is presented that provides an analysis of the optical properties of human skin, with particular regard to their applications in medicine. Included is a description of the primary interactions of light with skin and how these are commonly estimated using radiative transfer theory (RTT). This is followed by analysis of measured RTT coefficients available in the literature. Orders of magnitude differences are found within published absorption and reduced-scattering coefficients. Causes for these discrepancies are discussed in detail, including contrasts between data acquired in vitro and in vivo. An analysis of the phase functions applied in skin optics, along with the remaining optical coefficients (anisotropy factors and refractive indices) is also included. The survey concludes that further work in the field is necessary to establish a definitive range of realistic coefficients for clinically normal skin.

Optical properties of human skin.

A survey of the literature is presented regarding the simulation of port wine stain (PWS) skin color. Knowledge of PWS features, such as the depths and diameters of affected vessels, is essential for informing laser treatment. These may be determined through the inverse application of a skin model. The techniques which have been applied to achieve this are analyzed in detail. Radiative transfer (RT) is found to be the preferred method of simulation. By far the most common approximations to RT are the diffusion approximations, which have been applied successfully in the past and Monte Carlo techniques, which are now the methods of choice. As the requirements for improvement of laser treatment on an individual basis continues, the needs for further work towards accurate estimations of individual optical coefficients and robust, flexible simulation techniques are identified.

Simulating light transport through skin for color prediction of port wine stain lesions: a review.

The aim of this study was to assess the potential of employing a classification tool to objectively classify participants with clinically assessed movement faults (MFs) of the scapula. Six participants with a history of shoulder pain with MFs of the scapula and 12 healthy participants with no movement faults (NMFs) performed a flexion movement control test of the scapula, while scapular kinematic data were collected. Principal component scores and discrete kinematic variables were used as input into a classifier. Five out of the six participants with a history of pain were successfully classified as having scapular MFs with an accuracy of 72%. Variables related to the upward rotation of the scapula had the most influence on the classification. The results of the study demonstrate the potential of adopting a multivariate approach in objective classification of participants with altered scapular kinematics in pathological groups.

Paul H. Chappell

Electronics and Computer Sciences

University of Southampton

Measurement of Dynamic Scapular Kinematics Using an Acromion Marker Cluster to Minimize Skin Movement Artifact